Exemplary embodiments of the present invention relate to a motor vehicle parking lock device.
German patent document DE 10 2005 060 583 A1 discloses a motor vehicle parking lock device having a locking element for locking a parking lock piston in a positive-fit manner, and having a release unit having at least one electromagnetic actuator for releasing the parking lock piston.
German patent document DE 10 2006 049 639 A1 discloses a parking lock device that is locked by means of a hydraulic or pneumatic actuator.
European patent document EP 1 855 033 A2 discloses a motor vehicle parking lock device having a parking lock piston which is hydraulically or pneumatically actuatable and having a locking device, wherein the parking lock piston may be brought into the parking position by means of a spring.
U.S. patent document US 2007/125619 A1 discloses a motor vehicle parking lock device having at least one locking element for locking a parking lock piston in a positive-fit manner, and having a release unit that has at least one electromagnetic actuator for releasing the parking lock piston. The release unit has a second actuator acting parallel to the electromagnetic actuator and which is provided for releasing the parking lock piston at least in the event of a failure of the electromagnetic actuator.
Exemplary embodiments of the present invention are directed to a simple motor vehicle parking lock device.
Exemplary embodiments of the present invention are directed to a motor vehicle parking lock device having at least one locking element for locking a parking lock piston in a positive-fit manner, and having a release unit, which has at least one electromagnetic actuator for releasing the parking lock piston.
In accordance with exemplary embodiments of the present invention the release unit has a hydraulic and/or pneumatic actuator acting parallel to the electromagnetic actuator and which releases the parking lock piston at least in the event of a failure of the electromagnetic actuator. Redundant release of the parking lock piston may thus be achieved, so that the parking lock piston may be released in a particularly advantageous manner, even in the event of a failure and/or a defect of the electromagnetic actuator. A design of the motor vehicle parking lock device may thus be simplified, so that the motor vehicle parking lock device may be designed for a fairly large operating range in a particularly simple manner. A robust, simple motor vehicle parking lock device may be provided in this way. A “parking lock piston” should be understood as an axially movable piston which is movably coupled to a parking lock pawl for engaging and disengaging a parking lock. The term “locking the parking lock piston” should be understood as an axial fixing of the parking lock piston, and thus a retention of an engaged or disengaged state of the parking lock. The term “release of the parking lock piston” should be understood as a detachment of the axial fixing of the parking lock piston. In the present context, the term “parallel” should be understood as a magnetic force that is generatable by the electromagnetic actuator and a hydraulic and/or pneumatic force that is generatable by the hydraulic and/or pneumatic actuator have the same effect, specifically, release of the parking lock piston, whereby the release in each case may be carried out by the electromagnetic actuator or by the hydraulic and/or pneumatic actuator. The term “provided” should be understood as specially programmed, designed, equipped, and/or situated.
Further, in accordance with exemplary embodiments of the present invention, the locking element has a positive-fit contour provided for locking the parking lock piston in a hydraulically and/or pneumatically non-overpressurable manner. Reliable locking of the parking lock piston may thus be achieved, so that unintentional release of the parking lock piston may be avoided. The term “in a hydraulically and/or pneumatically non-overpressurable manner” should be understood as meaning that a release of the parking lock piston due to a hydraulic and/or pneumatic force acting on the parking lock piston that is provided for switching the parking lock piston is not possible.
Additionally, the motor vehicle parking lock device has a single-acting actuating cylinder that is provided for switching the parking lock piston into a non-parking position, and has a spring which is provided for switching the parking lock piston into a parking position. The motor vehicle parking lock device may be simplified in this way. A “single-acting actuating cylinder” should be understood as an actuating cylinder that is provided solely for forming a single pressure chamber that is provided for the hydraulic and/or pneumatic switching of the parking lock piston. The term “pneumatic switching of the parking lock piston” should be understood as an axial displacement of the parking lock piston into an axial position associated with the parking position or the non-parking position. A “parking position” should be understood as a position in which a parking lock is engaged. A “non-parking position” should be understood as a position in which the parking lock is disengaged and/or is designed as a driving position. A “pressure chamber” should be understood as a chamber which includes at least one stationary wall and at least one movable wall and which may be acted on hydraulically and/or pneumatically.
In particular, it is advantageous for the motor vehicle parking lock device to have an operating medium pressure supply, and a switching valve which in a first valve position fluidically connects the hydraulic and/or pneumatic actuator to the operating medium pressure supply, and in a second valve position fluidically connects the actuating cylinder to the operating medium pressure supply. The parking position and the non-parking position may thus be switched in a particularly advantageous manner. An “operating medium pressure supply” should be understood as a unit composed of hydraulic and/or pneumatic elements, for example a pump, a switching valve, a line, a diaphragm, and/or the like, which is/are necessary for supplying the switching valve with an operating medium.
It is also advantageous when the locking element is provided for locking the parking lock piston in the parking position and in the non-parking position. A particularly advantageous motor vehicle parking lock device may thus be provided in which the parking lock piston may be reliably locked in the parking position and in the non-parking position.
Furthermore, exemplary embodiments of the present invention are directed to a method for releasing a parking lock piston of a motor vehicle parking lock device, in particular a motor vehicle parking lock device according to the invention, in which the parking lock piston is released by an electromagnetic actuator and/or by a hydraulic and/or pneumatic actuator. An emergency release may thus be achieved in a particularly simple manner.
In addition, for the method a parking lock piston locked in a non-parking position is released by the hydraulic and/or pneumatic actuator, and a parking lock piston that is locked in a parking position is released by the electromagnetic actuator. An advantageous release of the parking position and of the non-parking position may be achieved in this way.
Further advantages result from the following description of the drawing.
One exemplary embodiment of the invention is illustrated in the drawing. The drawing, the description, and the claims contain numerous features in combination. Those skilled in the art will also advantageously consider the features individually and combine them into further meaningful combinations.